Climate Science Glossary

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All IPCC definitions taken from Climate Change 2007: The Physical Science Basis. Working Group I Contribution to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change, Annex I, Glossary, pp. 941-954. Cambridge University Press.

Cosmic Rays vs Climate

The Galactic Cosmic Ray (GCR) hypothesis is a "skeptic" argument that global warming is caused by periods of high solar activity when strong solar magnetic fields protect the Earth from GCRs. Some hypothesize that GCRs seed clouds and therefore fewer of them lead to less reflective clouds and more global warming, so strong solar activity with low GCR counts should correlate with increasing global temperature. This graphic debunks that myth without even needing to address the questionable hypothesis, by simply looking at the measured relationship between global temperature and GCR counts. Shown are 11-year running averages of the global average surface temperature since 1885 from NASA GISS (red) along with the GCR counts on Earth from Krivova & Solanki 2003 (blue). In recent decades when global temperature has been increasing, the GCR flux has also increased (note inverted GCR scale). Higher GCR counts should correspond to more reflective clouds and therefore global cooling rather than the observed global warming, so GCRs cannot be responsible for the observed temperature increase (also see this graphic). Similarly, direct solar activity isn't causing global warming either.